Impact of mechanical bowel preparation on the gut microbiome of patients undergoing left-sided colorectal cancer surgery: randomized clinical trial.

BACKGROUND: Postoperative complications after colorectal cancer surgery have been linked to the gut microbiome. However, the impact of mechanical bowel preparation using oral preparation agents or rectal enema on postoperative infections remains poorly understood. This study aimed to compare the impact of oral preparation and rectal enema on the gut microbiome and postoperative complications. METHODS: This open-label pilot RCT was conducted at the National Cancer Institute, Vilnius, Lithuania. Patients with left-side colorectal cancer scheduled for elective resection with primary anastomosis were randomized 1 : 1 to preoperative mechanical bowel preparation with either oral preparation or rectal enema. Stool samples were collected before surgery, and on postoperative day 6 and 30 for 16S rRNA gene sequencing analysis. The primary outcome was difference in ß-diversity between groups on postoperative day 6. RESULTS: Forty participants were randomized to oral preparation (20) or rectal enema (20). The two groups had similar changes in microbiome composition, and there was no difference in ß-diversity on postoperative day 6. Postoperative infections occurred in 12 patients (32%), without differences between the study groups. Patients with infections had an increased abundance of bacteria from the Actinomycetaceae family, Actinomyces genus, Sutterella uncultured species, and Enterococcus faecalis species. CONCLUSION: Mechanical bowel preparation with oral preparation or rectal enema resulted in similar dysbiosis. Patients who experienced postoperative infections exhibited distinct gut microbiome compositions on postoperative day 6, characterized by an increased abundance of bacteria from the Actinomycetaceae family, Actinomyces genus, Sutterella uncultured species, and Enterococcus faecalis species. REGISTRATION NUMBER: NCT04013841 (http://www.clinicaltrials.gov).

Is mechanical bowel preparation necessary to reduce surgical site infection following colon surgery? Protocol for a multicentre Canadian randomized controlled trial.

AIM: There is significant practice variation with respect to the use of bowel preparation to reduce surgical site infection (SSI) following colon surgery. Although intravenous antibiotics + mechanical bowel preparation + oral antibiotics (IVA + MBP + OA) has been shown to be superior to IVA + MBP and IVA, there are insufficient high-quality data from randomized controlled trails (RCTs) that directly compare these options. This is an important question, because if IVA + OA has similar effectiveness to IVA + MBP + OA, mechanical bowel preparation can be safely omitted, and the associated side effects avoided. The aim of this work is to compare rates of SSI following IVA + OA + MBP (MBP) versus IVA + OA (OA) for elective colon surgery. METHOD: This is a multicentre, parallel, two-arm, noninferiority RCT comparing IVA + OA + MBP versus IVA + OA. The primary outcome is the overall rate of SSI 30 days following surgery. Secondary outcomes are length of stay and 30-day emergency room visit and readmission rates. The planned sample size is 1062 subjects with four participating high-volume centres. Overall SSI rates 30 days following surgery between the treatment groups will be compared using a general linear model. Secondary outcomes will be analysed with linear regression for continuous outcomes, logistic regression for binary outcomes and modified Poisson regression for count data. CONCLUSION: It is expected that IVA + OA will work similarly to IVA + MBP + OA and that this work will provide definitive evidence showing that MBP is not necessary to reduce SSI. This is highly relevant to both patients and physicians as it will have the potential to significantly change practice and outcomes following colon surgery in Canada and beyond.

Influence of additional prophylactic oral antibiotics during mechanical bowel preparation on surgical site infection in patients receiving colorectal surgery.

BACKGROUND: Prophylactic antibiotics (PAs) are standard for preventing surgical site infections (SSIs) post-colorectal surgery. This study aims to compare the effect of additional empiric oral antibiotics (OAs) alongside routine PAs to identify SSI risk factors. METHODS: A retrospective observatory analysis was conducted from January 2019 to December 2022 at Asan Medical Center, Seoul, Korea. The cohort was divided into two groups: PA given 1 h before surgery and discontinued within 24 h, and OA administered empiric OAs during mechanical bowel preparation in addition to PA. RESULTS: From a total of 6736 patients, 3482 were in the PA group and 3254 in the OA group. SSI incidence showed no significant intergroup difference (p = 0.374) even after propensity score matching (p = 0.338). The multivariable analysis revealed male sex [odds ratio (OR): 2.153, 95% confidence interval (CI): 1.626-2.852, and p = 0.001], open surgery (OR: 3.335, 95% CI: 2.456-4.528, and p = 0.001), dirty wound (OR: 2.171, 95% CI: 1.256-3.754, and p = 0.006), and an operation time of more than 145 min (OR: 2.110, 95% CI: 1.324-3.365, and p = 0.002) as SSI risk factors. In rectal surgery subgroup, OA demonstrated a protective effect against SSI (OR: 0.613, 95% CI: 0.408-0.922, and p = 0.019) and in laparoscopic approach (OR: 0.626, 95% CI: 0.412-0.952, and p = 0.028). CONCLUSIONS: OA did not affect SSI incidence in colorectal surgeries. Male sex, open surgery, dirty wounds, and longer operation time were risk factors for SSI. However, for rectal and laparoscopic surgery, OA was a protective factor for SSI.

Is mechanical bowel preparation mandatory for elective colon surgery? A systematic review and meta-analysis.

BACKGROUND: Growing evidence demonstrates minimal impact of mechanical bowel preparation (MBP) on reducing postoperative complications following elective colectomy. This study investigated the necessity of MBP prior to elective colonic resection. METHOD: A systematic literature review was conducted across PubMed, Ovid, and the Cochrane Library to identify studies comparing the effects of MBP with no preparation before elective colectomy, up until May 26, 2023. Surgical-related outcomes were compiled and subsequently analyzed. The primary outcomes included the incidence of anastomosis leakage (AL) and surgical site infection (SSI), analyzed using Review Manager Software (v 5.3). RESULTS: The analysis included 14 studies, comprising seven RCTs with 5146 participants. Demographic information was consistent across groups. No significant differences were found between the groups in terms of AL ((P = 0.43, OR = 1.16, 95% CI (0.80, 1.68), I2 = 0%) or SSI (P = 0.47, OR = 1.20, 95% CI (0.73, 1.96), I2 = 0%), nor were there significant differences in other outcomes. Subgroup analysis on oral antibiotic use showed no significant changes in results. However, in cases of right colectomy, the group without preparation showed a significantly lower incidence of SSI (P = 0.01, OR = 0.52, 95% CI (0.31, 0.86), I2 = 1%). No significant differences were found in other subgroup analyses. CONCLUSION: The current evidence robustly indicates that MBP before elective colectomy does not confer significant benefits in reducing postoperative complications. Therefore, it is justified to forego MBP prior to elective colectomy, irrespective of tumor location.

The effect of preoperative mechanical bowel preparation in paediatric bowel surgery on postoperative wound related complications: A meta-analysis.

Mechanical bowel preparation (MBP), a routine nursing procedure before paediatric bowel surgery, is widely should in clinical practice, but its necessity remains controversial. In a systematic review and meta-analysis, we evaluated the effect of preoperative MBP in paediatric bowel surgery on postoperative wound-related complications in order to analyse the clinical application value of MBP in paediatric bowel surgery. As of November 2023, we searched four online databases: the Cochrane Library, Embase, PubMed, and Web of Science. Two investigators screened the collected studies against inclusion and exclusion criteria, and ROBINS-I was used to evaluate the quality of studies. Using RevMan5.3, a meta-analysis of the collected data was performed, and a fixed-effect model or a random-effect model was used to analyse OR, 95% CI, SMD, and MD. A total of 11 studies with 2556 patients were included. Most of studies had moderate-to-severe quality bias. The results of meta-analysis showed no statistically significant difference in the incidence of complications related to postoperative infections in children with MBP before bowel surgery versus those with No MBP, wound infection (OR 1.11, 95% CI:0.76 ~ 1.61, p = 0.59, I2 = 5%), intra-abdominal infection (OR 1.26, 95% CI:0.58 ~ 2.77, p = 0.56, I2 = 9%). There was no significant difference in the risk of postoperative bowel anastomotic leak (OR 1.07, 95% CI:0.68 ~ 1.68, p = 0.78, I2 = 12%), and anastomotic dehiscence (OR 1.67, 95% CI:0.13 ~ 22.20, p = 0.70, I2 = 73%). Patients' intestinal obstruction did not show an advantage of undergoing MBP preoperatively, with an incidence of intestinal obstruction (OR 1.95, 95% CI:0.55 ~ 6.93, p = 0.30, I2 = 0%). Based on existing evidence that preoperative MBP in paediatric bowel surgery did not reduce the risk of postoperative wound complications, we cautiously assume that MBP before surgery is unnecessary for children undergoing elective bowel surgery. However, due to the limited number of study participants selected for this study and the overall low quality of evidence, the results need to be interpreted with caution. It is suggested that more high quality, large-sample, multicenter clinical trials are required to validate our findings.

Association of bowel preparation with surgical-site infection in gynecologic oncology surgery: Post-hoc analysis of a randomized controlled trial.

OBJECTIVE: To determine the relationship between bowel preparation and surgical-site infection (SSI) incidence following colorectal resection during gynecologic oncology surgery. METHODS: This post-hoc analysis used data from a randomized controlled trial of patients enrolled from 03/01/2016-08/20/2019 with presumed gynecologic malignancy investigating negative-pressure wound therapy among those requiring laparotomy. Patients were treated preoperatively without bowel preparation, oral antibiotic bowel preparation (OABP), or OABP plus mechanical bowel preparation (MBP) per surgeon preference. Univariate and multivariable analyses with stepwise model selection for SSI were performed for confirmed gynecologic malignancies requiring colorectal resection. RESULTS: Of 161 cases, 15 (9%) had no preparation, 39 (24%) OABP only, and 107 (66%) OABP+MBP. The overall SSI rate was 19% (n = 31)-53% (n = 8/15) in the no preparation, 21% (n = 8/39) in the OABP alone, and 14% (n = 15/107) in the OABP+MBP groups (P = 0.003). The difference between OABP and OABP+MBP was non-significant (P = 0.44). The median length of stay was 9 (range, 6-12), 6 (range, 5-8), and 7 days (range, 6-10), respectively (P = 0.045). The overall complication rate (34%; n = 54) did not significantly vary by preparation type (P = 0.23). On univariate logistic regression analysis, OABP (OR, 0.23; 95% CI: 0.06-0.80) and OABP+MBP (OR, 0.14; 95% CI: 0.04-0.45) were associated with decreased SSI risk compared to no preparation (P = 0.004). On multivariate analysis, both methods of preparation retained a significant impact on SSI rates (P = 0.004). CONCLUSION: Bowel preparation is associated with reduced SSI incidence and is beneficial for patients undergoing gynecologic oncology surgery with anticipated colorectal resection. Further investigation is needed to determine whether OABP alone is sufficient.

Effect of acuity level and patient characteristics on bowel preparation quality: a retrospective cohort study of inpatient colonoscopies.

BACKGROUND AND AIMS: Colonoscopy is the primary method to detect mucosal abnormalities in the colon, rectum, and terminal ileum. Inadequate bowel preparation is a common problem and can impede successful visualization during colonoscopy. Although studies identified hospitalization as a predictor of inadequate bowel preparation, acuity of care vary greatly within this patient population. The current study aims to examine the effect of patient characteristics and care level predictors on inadequate bowel preparation quality within the inpatient setting. METHODS: This retrospective study was conducted in a single urban level 1 trauma medical center and included adult patients undergoing diagnostic colonoscopy while admitted in the hospital from January 1, 2015 to June 30, 2020. We examined the level of inpatient care between the General Medical Floor (GMF), Intensive Care Units (ICU) and Telemetry Unit (TU) and assessed this association with bowel preparation quality, adjusting for known and unknown predictors. RESULTS: Of 538 patients undergoing colonoscopy, 47.4% were admitted into TU, 43.7% into GMF and 8.9% into ICU. For the entire sample, 72.7% of patients achieved good or excellent preparation and quality of bowel preparation differed by care level (P = 0.01). Patients from the critical care units were less likely to achieve adequate bowel preparation when compared to GMF (Odds Ratio [OR] 0.36; 95% Confidence Interval [CI] 0.17,0.77), after adjusting for patient characteristics, medications, physical status, and preparation regimen. No significant difference in Bowel Preparation Quality (BPQ) was identified between patients from GMF and TU (OR 0.96; 95%CI 0.61, 1.52). Furthermore, adequate BPQ was associated with withdrawal time and cecal intubation, but not higher adenoma detection rates. CONCLUSIONS: Results suggest the ICU setting is an independent predictor for inadequate bowel preparation and patients with prior opioid and laxative use may be more likely to have inadequate bowel preparation in the hospital. Future interventions should prioritize preprocedural clinician meetings for critical care unit patients, including a more detailed readiness assessment and thorough medication history.

Oral antibiotics and mechanical bowel preparation for colorectal surgery: A prospective observational study of surgical site infection and microbial analysis.

PURPOSE: Surgical site infections (SSIs) are common in colorectal surgery. Mechanical bowel preparation (MBP) in conjunction with oral antibiotics (OABs) have been shown to reduce SSI rates. It however is still unclear which OABs to use, and how this can be implemented in practice. METHODS: This is a prospective observational study carried out in Swansea Bay University Health Board during 2019-2021, evaluating the introduction of OABs in a stepwise manner on the incidence of SSI in major colorectal surgery. A control group having MBP only was compared to two OAB groups: one group had MBP plus metronidazole only and the second MBP plus metronidazole and neomycin. A 30-day follow-up after surgery was ascertained via chart review and telephone contact. Logistic regression was performed to estimate the relation between OAB use and SSI, with adjustment for confounding. In a subset of patients, faecal samples were analysed through 16S rRNA amplicon sequencing before and after OAB treatment, depicting the impact of the gut microbiome. RESULTS: In total 160 patients were analysed: 46 patients had MBP only, whilst 76 patients had MBP plus metronidazole only and 38 patients had MBP with metronidazole/neomycin. The SSI rate in the entire cohort was 33.8%, whilst the adjusted ORs for the single- and dual-OAB groups were 0.76 (95% CI: 0.17-1.81) and 0.50 (95% CI: 0.17-1.52). The microbial analysis demonstrated that the relative abundance for many bacterial genera was changed before and after OAB treatment, but no link with SSI development could be shown. CONCLUSIONS: Introduction of OABs in conjunction with MBP in colorectal surgery is feasible, and may potentially lead to lower rates of SSI, as well as altering the community structure of the faecal microbiome. More research is needed, especially considering different OABs and mechanistic studies of the gut microbiome in the context of colorectal surgery.

Effect of preoperative oral antibiotics and mechanical bowel preparation on the prevention of surgical site infection in elective colorectal surgery, and does oral antibiotic regime matter? a bayesian network meta-analysis.

PURPOSE: Surgical site infection (SSI) impacts 5-20% of patients after elective colorectal surgery. There are varying reports on the effectiveness of oral antibiotics (OAB) with preoperative mechanical bowel preparation (MBP) in preventing SSI. We aim to determine the role of OAB and MBP in preventing SSI after elective colorectal surgery. We also determine if a specific OAB regimen will be more effective than others. METHODS: This study investigated the impact of OAB and MBP in patients undergoing elective colorectal surgery. PubMed, MEDLINE, Ovid, Cochrane Central Register of Controlled Trials, ACP Journal Club, and Embase databases were searched for randomized clinical trials (RCTs) published by June 2022. All RCTs comparing various preoperative bowel preparation regimens, including pairwise or multi-intervention comparisons, were included. To establish the role of OAB and MBP in preventing SSI, we conducted a Bayesian network meta-analysis on all RCTs. We further performed subgroup analysis to determine the most effective OAB regimen. RESULTS: Among included 46 studies with a total of 12690 patients, patients in the MBP + OAB group were less likely to have SSI than those having MBP-only (OR 0.55, 95% CrI 0.39-0.76), and without MBP and OAB (OR 0.52, 95% CrI 0.32-0.84). OAB regimen C (kanamycin + metronidazole) and A (neomycin + metronidazole) demonstrated a significantly reduced incidence of SSI, compared to regimen B (neomycin + erythromycin) with OR 0.24 (95% CrI 0.07-0.79) and 0.26 (95% CrI 0.07-0.99) respectively. CONCLUSIONS: OAB with MBP reduces the risk of SSI after elective colorectal surgery. Providing adequate aerobic and anaerobic coverage with OAB may confer better protection against SSI.

EAES, SAGES, and ESCP rapid guideline: bowel preparation for minimally invasive colorectal resection.

BACKGROUND: Variation exists in practice pertaining to bowel preparation before minimally invasive colorectal surgery. A survey of EAES members prioritized this topic to be addressed by a clinical practice guideline. OBJECTIVE: The aim of the study was to develop evidence-informed clinical practice recommendations on the use of bowel preparation before minimally invasive colorectal surgery, through evidence synthesis and a structured evidence-to-decision framework by an interdisciplinary panel of stakeholders. METHODS: This is a collaborative project of EAES, SAGES, and ESCP. We updated a previous systematic review and performed a network meta-analysis of interventions. We appraised the certainty of the evidence for each comparison, using the GRADE and CINeMA methods. A panel of general and colorectal surgeons, infectious diseases specialists, an anesthetist, and a patient representative discussed the evidence in the context of benefits and harms, the certainty of the evidence, acceptability, feasibility, equity, cost, and use of resources, moderated by a GIN-certified master guideline developer and chair. We developed the recommendations in a consensus meeting, followed by a modified Delphi survey. RESULTS: The panel suggests either oral antibiotics alone prior to minimally invasive right colon resection or mechanical bowel preparation (MBP) plus oral antibiotics; MBP plus oral antibiotics prior to minimally invasive left colon and sigmoid resection, and prior to minimally invasive right colon resection when there is an intention to perform intracorporeal anastomosis; and MBP plus oral antibiotics plus enema prior to minimally invasive rectal surgery (conditional recommendations); and recommends MBP plus oral antibiotics prior to minimally invasive colorectal surgery, when there is an intention to localize the lesion intraoperatively (strong recommendation). The full guideline with user-friendly decision aids is available in https://app.magicapp.org/#/guideline/LwvKej . CONCLUSION: This guideline provides recommendations on bowel preparation prior to minimally invasive colorectal surgery for different procedures, using highest methodological standards, through a structured framework informed by key stakeholders. Guideline registration number PREPARE-2023CN045.

Mechanical bowel preparation with or without oral antibiotics for rectal resection for cancer (REPCA trial): a study protocol for a multicenter randomized controlled trial.

BACKGROUND: There is still a lack of randomized trials assessing the clinical value of mechanical bowel preparation (MBP) and oral antibiotics (OA) before rectal surgery. Existing studies are inconsistent regarding OA. The aim of this study is to examine the role of MBP with or without OA (using Alfa Normix®) on postoperative complications in patients undergoing rectal resection for cancer. METHODS: We are conducting a prospective multicenter randomized controlled trial comparing MBP (Moviprep®) with OA (Alfa Normix®) versus MBP alone in patients undergoing elective rectal resection for cancer. Patients with rectal or rectosigmoid cancer are randomized in a 1:1 allocation ratio. The primary endpoint is incisional surgical site infection (SSI) assessed within 30 days after surgery. Secondary endpoints are anastomotic leakage (AL), organ/space SSI, other postoperative complications, intraoperative complications, operation time, bowel preparation quality, bowel preparation adherence. Intention-to-treat and per protocol analyses will be performed. CONCLUSIONS: The results of the REPCA trial will demonstrate whether MBP + OA is superior to MBP alone in rectal cancer surgery. This trial might influence current preoperative practice and improve postoperative outcomes.

Digital Navigation Improves No-Show Rates and Bowel Preparation Quality for Patients Undergoing Colonoscopy: A Randomized Controlled Quality Improvement Study.

OBJECTIVES: Because of high historical no-show rates and poor bowel preparation quality in our unit, we sought to evaluate whether text message navigation for patients scheduled for colonoscopy would reduce no-show rates and improve bowel preparation quality compared with usual care. METHODS: We performed a randomized controlled quality improvement study from April to August 2019 in an urban academic endoscopy unit. All patients scheduled for colonoscopy were randomly assigned to a control group that received usual care (paper instructions/nursing precalls) or to the intervention group that received usual care plus the text message program [short message service (SMS)]. The program provided timed-release instructions on dietary modifications and bowel preparation before colonoscopy. The primary outcome was no-shows. Secondary outcomes were no-show/same-day cancellations, no-show/cancellations within 7 days of the procedure, and bowel preparation quality. RESULTS: A total of 1625 patients were randomized (SMS=833, control=792). No-show rates were significantly lower in the SMS group compared with the control group (8% vs. 14%; P<0.0001). Similar results were found for no-show/same-day cancellations (10% vs. 16%; P=0.0003), and no-show/cancellations within 7 days (18% vs. 26%; P=0.0008). There was no difference in adequate bowel preparation for all colonoscopies between the groups (89% vs. 87%; P=0.47). However, rates of adequate bowel preparation for screening/surveillance colonoscopies were significantly higher in SMS versus control groups (93% vs. 88%; P=0.04). CONCLUSIONS: Text message navigation for patients scheduled for colonoscopy improved the quality of colorectal cancer screening by decreasing no-show rates and increasing adequate bowel preparation rates in patients undergoing screening colonoscopy compared with usual care.

Impact of bowel preparation on elective colectomies for diverticulitis: analysis of the NSQIP database.

BACKGROUND: Recent data based on large databases show that bowel preparation (BP) is associated with improved outcomes in patients undergoing elective colorectal surgery. However, it remains unclear whether BP in elective colectomies would lead to similar results in patients with diverticulitis. The purpose of this study was to investigate whether bowel preparation affected the surgical site infections (SSI) and anastomotic leakage (AL) in patients with diverticulitis undergoing elective colectomies. STUDY DESIGN: We identified 16,380 diverticulitis patients who underwent elective colectomies from the American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) colectomy targeted database (2012-2017). Multivariate logistic regression models were employed to investigate the impact of different bowel preparation strategies on postoperative complications, including SSI and AL. RESULTS: In the identified population, a total of 2524 patients (15.4%) received no preparation (NP), 4715 (28.8%) mechanical bowel preparation (MBP) alone, 739 (4.5%) antibiotic bowel preparation (ABP) alone, and 8402 (51.3%) MBP + ABP. Compared to NP, patients who received any type of bowel preparations showed a significantly decreased risk of SSI and AL after adjustment for potential confounders (SSI: MBP [OR = 0.82, 95%CI: 0.70-0.96], ABP [0.69, 95%CI: 0.52-0.92]; AL: MBP [OR = 0.66, 95%CI: 0.51-0.86], ABP [0.56, 95%CI: 0.34-0.93]), where the combination type of MBP + ABP had the strongest effect (SSI:OR = 0.58, 95%CI:0.50-0.67; AL:OR = 0.46, 95%CI:0.36-0.59). The significantly decreased risk of 30-day mortality was observed in the bowel preparation of MBP + ABP only (OR = 0.32, 95%CI: 0.13-0.79). After the further stratification by surgery procedures, patients who received MBP + ABP showed consistently lower risk for both SSI and AL when undergoing open and laparoscopic surgeries (Open: SSI [OR = 0.51, 95%CI: 0.37-0.69], AL [OR = 0.47, 95%CI: 0.25-0.91]; Laparoscopic: SSI [OR = 0.58, 95%CI: 0.47-0.72, AL [OR = 0.49, 95%CI: 0.35-0.68]). CONCLUSIONS: MBP + ABP for diverticulitis patients undergoing elective open or laparoscopic colectomies was associated with decreased risk of SSI, AL, and 30-day mortality. Benefits of MBP + ABP for diverticulitis patients underwent robotic surgeries warrant further investigation.

Reinforced education by short message service improves the quality of bowel preparation for colonoscopy.

PURPOSE: This study aimed to evaluate the effect of reinforced education (RE) by short message service (SMS) on the bowel preparation quality of patients undergoing colonoscopy. METHODS: Randomized controlled trials (RCTs), conducted on the effect of RE by SMS on bowel preparation for colonoscopy from inception to November 1, 2021, were queried from databases, including PubMed, Web of Science, the Cochrane Library, and EMBASE. After extracting the data, meta-analysis was conducted using Review Manager Software version 5.3. RESULTS: A total of seven RCTs with 5889 patients were subjected to meta-analysis. The rate of adequate bowel preparation in the SMS group (81.7%) was significantly higher than that in the control group (75.7%) (RR: 1.10, 95% CI: 1.03-1.17, p < 0.01). Four studies suggested that RE by SMS significantly reduced the non-attendance rate of patients for scheduled colonoscopy (RR: 0.74, 95% CI: 0.56-0.99, p < 0.05). CONCLUSION: RE by SMS for patients undergoing colonoscopy can significantly improve the quality of bowel preparation and decrease the non-attendance rate of patients for scheduled colonoscopy.

Are colorectal surgery patients willing to accept an increased risk of surgical site infection to avoid mechanical bowel preparation? Implications for future trial design.

AIM: Recent evidence has shown no difference in the risk of surgical site infection (SSI) with oral antibiotics alone (OA) and oral antibiotics in combination with mechanical bowel preparation (OA + MBP), suggesting that the use of MBP may be safely avoided. The aim of this work was to determine the absolute risk of SSI that patients would accept with OA relative to OA + MBP. METHOD: Standardized, in-person interviews were conducted using the threshold task with patients attending colorectal surgery clinics who had previously had MBP. Participants were asked which option they preferred when the absolute risk of SSI was 7% for both options. Next, their switch point was determined by increasing the risk of SSI with OA by 1% intervals until their preference changed from OA to OA + MBP. Median switch point scores were reported and represented the absolute increased risk of SSI that patients would accept with OA relative to OA + MBP. RESULTS: Fifty patients completed the interview. All participants chose OA over OA + MBP when the risk of SSI was 7% for both options. Switch points ranged from 8% to 25%, with a median of 10%, indicating that participants were willing to accept up to a 3% increase in absolute risk of developing a SSI with OA to avoid MBP. CONCLUSIONS: The results showed that patients are willing to accept an increased risk of up to 3% for SSI with OA relative to OA + MBP. Incorporating patient preferences into the planning of future trials has the potential to improve the uptake of trial results into clinical practice.

The Impact of Patient Education Level on Split-Dose Colonoscopy Bowel Preparation for CRC Prevention.

INTRODUCTION: AGA guidelines emphasize split-dose bowel preparation (BP) to ensure high-quality colonoscopy for the prevention of colorectal cancer (CRC). Split dose results in higher-quality preparation, but understanding instructions might be more difficult. Lower education levels may negatively influence BP quality. The confounding role of education level on BP quality was investigated. METHODS: This was a cross-sectional study of 60 patients given split-dose BP. Patients consented and were asked three Likert scale questions based on BP instructions before the procedure. Compliance was self-reported. BP adequacy and the number of adenomas were recorded. BP was characterized as adequate (excellent, good) or inadequate (fair, poor). Data was analyzed with chi-square, odds ratio, Mann-Whitney, and regression analysis. RESULTS: Thirty-one (52%) patients were high school graduates, 21 (38%) completed some college, and 6 (10%) were college graduates. College-educated patients had adequate BP (72%) more often than high school graduates (51%) (p = 0.02). Adenoma findings were not significantly different. The Likert scale mean ranks for patient understanding and reviewing of instructions were comparable between the two groups. Patient rating of scheduler explanations of the importance of following instructions was significantly better in the college group (mean ranks 2.59 and 1.83, respectively; p = 0.018). DISCUSSION: Patient education level significantly affected the success of BP. Split BP can be more complex to comprehend, and instructions should consider patient education level. Specific intervention programs should be implemented to advise patients with less education that poor preparation may result in missed advanced neoplasias and subsequent procedures.

A Safety and Efficacy Comparison of a New Sulfate-Based Tablet Bowel Preparation Versus a PEG and Ascorbate Comparator in Adult Subjects Undergoing Colonoscopy.

INTRODUCTION: A new tablet-based bowel prep for colonoscopy has been developed containing poorly absorbed sulfate salts which act to retain water within the intestinal lumen resulting in a copious diarrhea, thereby cleansing the bowel. This study evaluated the safety and efficacy of these oral sulfate tablets (OST) compared with a US FDA-approved bowel prep solution containing PEG3350, electrolytes, and ascorbate (polyethylene glycol and ascorbate [PEG-EA]). METHODS: Five hundred fifteen adult patients (mean 57y) were enrolled in this single-blind, multicenter, noninferiority study. Subjects were assigned either PEG-EA or OST to be administered in a split-dose regimen starting the evening before colonoscopy. PEG-EA was taken according to its approved labeling (1 L of prep solution with 16 oz. of additional water) in the evening and again in the morning. OST patients took a total of 24 tablets. OST patients were administered 12 tablets in the evening, and the following morning. Patients consumed 16 ounces of water with each dose of 12 tablets and drank an additional 32 oz. of water with each dose. Colonoscopies were performed by blinded investigators. Cleansing efficacy was evaluated globally and segmentally using a 4-point scale (Excellent-no more than small bits of feces/fluid which can be suctioned easily; achieves clear visualization of the entire colonic mucosa. Good-feces and fluid requiring washing and suctioning, but still achieves clear visualization of the entire colonic mucosa. Fair-enough feces even after washing and suctioning to prevent clear visualization of the entire colonic mucosa. Poor-large amounts of fecal residue and additional bowel preparation required). Scores of Good or Excellent were considered to be a success. Safety was assessed by spontaneously reported adverse events, solicited ratings of expected prep symptoms, and laboratory testing. RESULTS: A high rate of cleansing success was seen with OST (92%), which was noninferior to PEG-EA (89%). Only a small proportion of subjects rated their expected gastrointestinal symptoms as severe (<5% for both preps). No clinically significant differences were seen between preps for chemistry and hematology parameters. No serious adverse experiences were reported with OST. DISCUSSION: Sulfate tablets achieved a high level of cleansing in the study, comparable with US FDA-approved preps. OST was noninferior to PEG-EA in this study and achieved significantly more Excellent preps overall and in the proximal colon. The OST prep was well-tolerated, with a similar rate of spontaneously reported adverse experiences to PEG-EA and a low rate of severe expected gastrointestinal symptoms.

Efficacy and Safety of Over-the-Counter Therapies for Chronic Constipation: An Updated Systematic Review.

INTRODUCTION: Constipation is commonly treated with over-the-counter (OTC) products whose efficacy and safety remain unclear. We performed a systematic review of OTC therapies for chronic constipation and provide evidence-based recommendations. METHODS: We searched PubMed and Embase for randomized controlled trials of ≥4-week duration that evaluated OTC preparations between 2004 and 2020. Studies were scored using the US Preventive Services Task Force criteria (0-5 scale) including randomization, blinding, and withdrawals. The strengths of evidence were adjudicated within each therapeutic category, and recommendations were graded (A, B, C, D, and I) based on the level of evidence (level I, good; II, fair; or III, poor). RESULTS: Of 1,297 studies identified, 41 met the inclusion criteria. There was good evidence (grade A recommendation) for the use of the osmotic laxative polyethylene glycol (PEG) and the stimulant senna; moderate evidence (grade B) for psyllium, SupraFiber, magnesium salts, stimulants (bisacodyl and sodium picosulfate), fruit-based laxatives (kiwi, mango, prunes, and ficus), and yogurt with galacto-oligosaccharide/prunes/linseed oil; and insufficient evidence (grade I) for polydextrose, inulin, and fructo-oligosaccharide. Diarrhea, nausea, bloating, and abdominal pain were common adverse events, but no serious adverse events were reported. DISCUSSION: The spectrum of OTC products has increased and quality of evidence has improved, but methodological issues including variability in study design, primary outcome measures, trial duration, and small sample sizes remain. We found good evidence to recommend polyethylene glycol or senna as first-line laxatives and moderate evidence supporting fiber supplements, fruits, stimulant laxatives, and magnesium-based products. For others, further validation with more rigorously designed studies is warranted.

Preoperative oral antibiotics with versus without mechanical bowel preparation to reduce surgical site infections following colonic resection: Protocol for an international randomized controlled trial (ORALEV2).

AIM: Surgical site infections (SSIs) are common after colonic surgery. SSIs can cause relevant morbidity and increase costs of care. Preoperative oral antibiotics can reduce the incidence of SSIs after resection of the colon, but the role of mechanical bowel preparation (MBP) is debated. This study aims to assess the impact of a combined regimen of oral antibiotics and MBP on SSIs after colonic surgery. METHODS: An international, multicentre, pragmatic, adaptive, parallel-group, randomized controlled trial will be conducted across Europe. Adult patients scheduled to undergo elective colonic resection will be assessed for inclusion. Patients will be randomized into one of two treatment arms: (1) preoperative oral antibiotics without MBP (control); (2) preoperative oral antibiotics with MBP (experimental). All patients will receive intravenous antibiotics at anaesthetic induction. The primary aim will be 30-day SSI, assessed by a blinded nurse. Additional end-points include safety, morbidity and mortality, satisfaction with the preparation, time to return of bowel function, time to complete recovery and time to discharge, long-term results. Analyses will be performed with a modified intention-to-treat approach. Interim analyses are planned. DISCUSSION: This will be the first randomized clinical trial to assess the efficacy and safety of preoperative oral antibiotics plus MBP versus preoperative oral antibiotics only, before colonic surgery. The knowledge obtained could help to establish the ideal preparation for patients scheduled to undergo resection of the colon. Full protocol NCT04161599.

Sodium phosphate is superior to polyethylene glycol in constipated patients undergoing colonoscopy: a systematic review and meta-analysis.

BACKGROUND: Constipation is an important and highly prevalent predictor of inadequate bowel preparation during colonoscopy. In North America, between 2 and 28% of the general population suffer from constipation. Despite the high prevalence of constipation, to our knowledge, no meta-analysis on the optimal bowel preparation for constipated patients has been performed. We aimed to systematically review the literature to determine the ideal bowel preparation regiment for patients with chronic constipation. METHODS: A comprehensive search of electronic databases (MEDLINE, EMBASE, SCOPUS, and Web of Science) was performed. We included studies that assessed the quality of bowel preparation in constipated patients receiving different agents prior to colonoscopy. The primary outcome was colon cleanliness. Secondary outcomes included tolerability of the bowel preparation and serious adverse events. RESULTS: Preliminary database search yielded 1581 articles after duplicates were removed. After screening of the titles and abstracts using the exclusion criteria, 358 full-text articles were retained. Full-text articles were reviewed and eight studies meeting the inclusion criteria were included for qualitative synthesis. Three randomized controlled trials identified a total of 1636 constipated patients, of whom 225 were eligible for meta-analysis. Of those, 107 (47.6%) received NaP and 118 (52.4%) received PEG. Patients receiving NaP before colonoscopy had a higher chance of a successful bowel preparation than patients receiving PEG (OR 1.87, CI 1.06 to 3.32, P = 0.003). In the studies comparing PEG to NaP, two found that NaP resulted in greater tolerability of the bowel preparation and one study found that PEG resulted in superior tolerability. CONCLUSIONS: In chronically constipated patients undergoing colonoscopy, the use of NaP may result in superior colonic cleanliness when compared to PEG, however, quality of evidence was low. Further high-quality studies are required to delineate the optimal bowel preparation in patients with constipation.